Short answer
Standing seam panels attach with hidden clips under interlocking seams, so no fasteners pierce the face of the panel and the panels can slide as they heat and cool. Exposed-fastener panels overlap and are screwed through the face with gasketed screws; they are generally less labor to install, but the washers and screws need checking over time. Standing seam fits most homes and finished buildings; exposed-fastener panels fit barns, sheds, shops and tighter budgets.
The barn roof and the house roof
Maybe you are putting a roof on a shop and a house in the same year, or a roofer has offered you a screw-down panel at one price and standing seam at another. Both are metal, both come in the same colors, and from the road they can look alike. Up close they are built on different ideas about where the fasteners go, and that one difference drives almost everything else.
The company's Anderson page lists standing seam and corrugated among the metal roofs it installs, and its residential metal roofing page covers homes, garages, hobby shops and ranch or farm homes. This guide compares the two systems point by point so you can decide which belongs on which building.
Where the screws are, and why it matters
The Insurance Institute for Business and Home Safety (IBHS) sorts metal panels into two groups. Exposed-fastener panels, including 5-V, rib and tile-profile panels, overlap at their sides and are screwed through the panel face; IBHS calls them lapped panels. Concealed-fastener panels, meaning standing seam and snap lock, are held by clips hidden under the seam, so the screws never pass through the part of the panel that carries water.
On an exposed-fastener roof, every screw is a sealed hole. The IBHS low-slope metal guide says these fasteners must include EPDM washers and warns against over- or under-tightening them, because the washer is what keeps water out. IBHS also notes that the rubber gaskets around exposed fasteners can deteriorate with age, and that fasteners can back out of metal roofs and need to be reinstalled.
On a standing seam roof, the IBHS guide describes concealed hold-down clips that secure the panel to the substructure, with sliding clips that let the roof expand and contract. The remaining exposed fasteners are at trim, flashing and some penetrations. The guide on how a standing seam roof works walks through those parts one by one.
| Question | Standing seam | Exposed-fastener panel |
|---|---|---|
| How is it attached? | Concealed clips under the seam, screwed to the deck (IBHS) | Gasketed screws through the panel face into purlins or deck (IBHS) |
| How does it handle heat movement? | Sliding clips let the panels expand and contract (IBHS low-slope guide) | Panels are pinned at every screw; movement works against the fastener and washer |
| What needs checking later? | Flashing, trim and sealant at penetrations (IBHS: may need annual inspection and resealing) | Rubber washers that age and screws that back out (IBHS) |
| Lowest code slope (2021 IRC R905.10.2) | 1/4 in 12 for standing-seam systems | 3 in 12 without lap sealant; 1/2 in 12 with approved lap sealant |
| Where it usually goes | Homes, churches, offices, retail, finished shops | Barns, sheds, equipment buildings, carports, porches, budget homes |
| Labor to install | Generally more | Generally less |
Heat, movement and the long-panel problem
Metal panels grow in the afternoon sun and shrink on a cold night. The National Park Service, in its brief on historic roofing, notes that wear and metal failure at joints can come from the metal's repeated movement with thermal changes. The longer the panel, the more it moves.
An exposed-fastener panel is pinned at every screw, so that movement works against the fastener and its washer, day after day. A standing seam panel on sliding clips moves as a unit while the clips stay put. This is the main reason standing seam is favored for long runs and for buildings where a leak would be costly, and why the company's post on standing seam roof clips spends so much time on fixed versus floating clips and the insulation under them.
Sealants are part of the same story. The Metal Roofing Alliance buyer's guide says thermal movement, expansion and contraction are the most common reasons substrate-compatible sealants are used, and that installers should use the sealants the panel manufacturer approves. Either system can be done well; the exposed-fastener one simply has more places that depend on a seal.
Upkeep, looks, slope and cost in plain terms
Four practical differences decide most of these choices.
- Upkeep. Exposed-fastener roofs need their screws looked at over time; IBHS says to inspect fasteners, particularly exposed ones. Standing seam roofs need attention at flashing and penetrations instead; the IBHS low-slope guide says roof penetrations and skylights on a metal panel roof may need to be inspected annually and resealed as needed. Neither is maintenance-proof. The company's roof repair and maintenance page covers inspection and preventative maintenance for both.
- Looks. Standing seam shows clean vertical lines with no visible screws. Exposed-fastener panels show rows of screw heads, which color-matched fasteners soften but do not hide. On a barn that is rarely a concern; on a front-facing house roof it often is.
- Slope. The 2021 International Residential Code (Section R905.10.2) allows standing-seam systems down to one-quarter unit vertical in 12 units horizontal, while lapped, nonsoldered-seam panels need 3 in 12 without lap sealant or one-half in 12 with approved lap sealant. South Carolina adopted the 2021 codes effective January 1, 2023, with state modifications; ask the Anderson County or City of Anderson building department what applies to your address.
- Cost. Standing seam is generally more labor: the panels are often formed to length, the clips are set one by one, and some seams are closed with a seaming tool after installation. Exposed-fastener panels generally go on faster with fewer parts. Get both quoted as line items so you can see where the difference comes from; the guide on what a roofing estimate should include shows what to look for.
Which one fits which building
There is no single right answer, but the pattern across the Upstate is consistent. Standing seam goes on buildings people live and work in, where appearance and a long service interval matter. Exposed-fastener panels go on buildings that shelter equipment, animals, vehicles or inventory, where the budget and the speed of the job matter more.
For a house, standing seam is the usual recommendation, and metal shingles or stone-coated steel are the alternatives if you want a shingle look; the types of metal roofing guide covers those. For a pole barn, run-in shed, carport or equipment building, an exposed-fastener panel on purlins is the normal choice, and the company's post on metal panels for agricultural buildings covers coatings, ventilation and livestock conditions that matter more than the fastener type.
Shops and garages sit in the middle. A heated, finished hobby shop attached to the house often gets standing seam to match; a detached cold-storage building often gets exposed-fastener panels. Churches, offices and retail generally use standing seam on sloped roofs and a membrane system where the roof is near flat.
When neither is the right call, and what to do next
If your roof is nearly flat, a lapped metal panel is the wrong product and even standing seam may be marginal; look at the flat roof systems page first. If an existing exposed-fastener roof is leaking at a few screws, a repair visit that replaces fasteners and reseals may be all you need, not a new roof. The company's FAQ page addresses the screw question directly.
If you want the look of shingles, neither panel type will give it to you; metal shingles, stone-coated steel or asphalt shingles will. And if the budget simply is not there for standing seam on a house, a well-installed exposed-fastener roof with a plan to check the fasteners is a legitimate choice, not a mistake.
Next step: ask for both systems quoted on the same roof, with panel profile, gauge, coating, fastener type and underlayment written in. Anderson Metal Roofing and Shingles gives free quotes, offers virtual consultations by Zoom or FaceTime, and verifies all measurements on site, which can adjust the price. Start at the residential metal page or request a quote.
Frequently asked questions
Do exposed fastener metal roofs leak?
Not when they are installed and maintained well, but every screw is a sealed hole that depends on its washer. The IBHS low-slope metal guide requires EPDM washers on exposed fasteners and warns against over- or under-tightening them, and IBHS notes the rubber gaskets can deteriorate with age and screws can back out. Leaks on these roofs usually show up at aging fasteners, end laps and penetrations, which is why a periodic look from the ground matters.
How often should the screws on a metal roof be checked or replaced?
No official source we opened gives a fixed interval. IBHS says fasteners, particularly exposed fasteners, should be inspected, and that gaskets age and screws can back out. A reasonable habit is to look from the ground each spring and after a storm for shiny or raised screw heads, rust rings or streaks, and to have a roofer check up close when you see them. The company's FAQ page addresses the screw question for roofs it installs.
Is standing seam worth the extra cost over a screw-down roof?
It depends on the building. On a house or finished building, the hidden fasteners, the room for thermal movement and the cleaner look are usually what people are paying for, and the lower slope allowance can matter too. On a barn, shed or equipment building, those advantages often do not justify the added labor, and an exposed-fastener panel with a plan to check the screws is the sensible choice. Ask for both quoted as line items.
Can you put an exposed fastener metal roof on a house?
Yes, and many Upstate homes have one, especially on additions, porches and budget builds. IBHS lists exposed-fastener panels as a normal metal roof type. Plan for the slope rules (the 2021 IRC requires 3 in 12 without lap sealant), a proper underlayment over the deck, good trim and flashing details, and periodic fastener checks. If you want no visible screws or your roof has long runs, standing seam is the alternative to price against it.
Which is better for a barn or shop, standing seam or screw-down panels?
For most barns, sheds and cold shops, exposed-fastener panels on purlins are the normal choice because they are generally less labor and the look of screw heads is not a concern. For a heated, finished shop attached to a house, standing seam is often chosen to match the house and avoid fastener upkeep. The company's agricultural buildings post covers coating, ventilation and livestock conditions, which matter more than the fastener type on a working barn.
Next: what to check before you act
If one option seems to fit, the next guide walks through what to check and what to ask before you sign anything.
Sources
- IBHS: Roof 101
- IBHS RICOWI Roof Guide: Low-Slope Metal
- IBHS: Natural Weathering and Hazard Exposure
- 2021 International Residential Code, Chapter 9 Roof Assemblies (ICC)
- SC Building Codes Council: Building Code Adoption (SC LLR)
- National Park Service, Preservation Brief 4: Roofing for Historic Buildings (PDF)
- Metal Roofing Alliance: Residential Metal Roofing Buyer's Guide (PDF)
- Anderson Metal Roofing and Shingles: Advantages of Metal Panels for Agricultural Buildings
Written by Anderson Metal Roofing and Shingles. Facts checked against the sources above on November 6, 2026. This guide is general information for property owners in the Anderson, SC area, not advice about your roof. Codes, standards and insurance rules change and local practice varies; confirm details with your installer, your insurer and the building department before you act.
